Swingable rain cover for vertical exhaust pipes with stop means

ABSTRACT

A cover assembly is provided to be secured to the upper end of an exhaust pipe of an internal combustion engine maintained outdoors in such a manner such that a cap forming part of the assembly will cover the end of the exhaust pipe when the engine is quiescent. When exhaust gases exert pressure in the pipe during operation of the engine the cap will be raised against gravity off the end of the pipe to permit the gases to escape. The movement of the cap between open and closed positions is a rocking movement about a pivot and normally results in considerable clatter as the parts strike metal. Means are provided by the invention to reduce the clatter.

BACKGROUND OF THE INVENTION

This invention is an improvement over the structures of U.S. Pat. Nos.2,983,216 and 4,059,045 which are incorporated herein by reference.

The invention relates to protective caps or rain covers for the openends of upright exhaust pipes of internal combustion engines. Suchcovers are mounted for rocking movement on exhaust stacks to prevententry of rain, insects, dust and the like when the engines are notoperating. More particuarly, the invention relates to means forpreventing, or at least reducing, the loud noises associated with theopening and closing of the covers.

Among the known prior art directed to attempting to reduce the noise ofrain covers is a "Weather Cap Construction" disclosed in U.S. Pat. No.3,523,499. The present invention distinguishes over this patent byvirtue of a novel combination with a rain cover of improved stop meansand bumpers as set forth hereinafter in the body of the specification.

The structure of the prior art U.S. Pat. No. 3,523,499 is complex andexpensive in that in order to make the combination of the fulcrum armand the clamping structure out of an integral member of sheet metal itis necessary to utilize sheet metal that has a relatively widedimension. The fulcrum arm and clamp structure must either be stampedfrom blanks which are individually cut or, if stamped in a progressivedie on a continuous basis must be made from strip material that is widerthan the width of either the clamp portion or the leg portion. In eithercase the device is expensive to manufacture.

The invention herein utilizes a structure in which the clamp portion andthe pivot support are formed of strip material whereby not only is therepractically no scrap during fabrication, but the forming and shaping canbe effected in bending, punching, welding and the like fixtures ratherthan in expensive dies as required for the said U.S. Pat. No. 3,523,499.

Still another problem with prior art devices like those of the said U.S.Pat. No. 3,523,499 is that they occupy large space. The vertical profileof the exhaust stack of a vehicle upon which they are installed isincreased and they require larger containers for shipment and storage.The invention on the other hand, by virtue of its novel structure,provides a very low profile. This is achieved by making the clamp andarm support out of strap material, having the pivot and clampingfastener in horizontal alignment and by a major portion of thecounterweight vane below the clamping means rather than above it.

A further problem which is solved by the invention is the wearing out ofplastic bumper means. According to the invention, the bumper means arereadily removable and replaceable in one case and prevented fromextrusion flow in another case.

SUMMARY OF THE INVENTION

Rain covers or rain caps according to the invention comprise a clampformed of two metal straps which are secured together face to face for aportion of their combined length and formed in a circle and adapted tofit around an exhaust stack at a second portion of their combinedlength. Each metal strap has an extension, or ear, at the end of thesecond portion which is perforated cooperatively to receive a bolt orother fastener to secure the clamp to an exhaust stack. A balance arm,bearing a dish-like cover, is pivotally supported by the clamp at alocation in horizontal alignment with the fastener, so that when theclamp is mounted on a stack the balance arm will swing between oneposition in which the weight of the cover causes it to close the upperend of the exhaust stack, and another position in which exhaust gasesforce the cover to swing up off the stack. Stop means are provided onthe balance arm member and plastic bumper means are provided on theclamp member. The stop means and the bumper means are placed so that, asthe cover opens and closes, the stop means and the bumper means willstrike each other, preventing parts of the balance arm member fromdirectly striking either the end of the exhaust pipe or the clamp memberthereby reducing the clatter which normally occurs as the cover opensand closes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tractor wherein a protective coverassembly embodying the invention is shown installed in a closed positionupon the upstanding exhaust stack;

FIG. 2 is a side elevational view with parts broken away and showing theprotective cover of the invention installed on an exhaust stack;

FIG. 3 is a fragmentary cross sectional view taken through line 3--3 ofFIG. 2 and in the direction indicated;

FIG. 4 is a top plan view of the protective cover assembly of FIG. 2;

FIG. 5 is a fragmentary cross sectional view taken through lines 5--5 ofFIG. 4 and in the indicated direction, illustrating a bumper bushing ofthe invention;

FIG. 6 is a view similar to that of FIG. 2 but of a modified form of theinvention;

FIG. 7 is a top plan view of the rain cover device of FIG. 6;

FIG. 8 is a fragmentary perspective view of a portion of the rain coverdevice of FIG. 6 showing the manner in which the bumper means areinstalled; and

FIG. 9 is a horizontal sectional view taken generally along the line9--9 of FIG. 8 and in the indicated direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIG. 1, there is shown a rain cover assembly or device 20according to the invention which is secured by a support or clamp member12 to an upstanding exhaust stack or pipe 11 of a heavy duty vehicle 10.The rain cover is shown closed, in the position it will be held bygravity when the vehicle is inoperative and no exhaust gases are beingexpelled from the exhaust stack 11. When exhaust gases exert pressure inthe column the rain cover will swing open, permitting the gas to escape.

As shown in FIG. 2, the rain cover assembly 20 includes a support orclamp member 12, a balance arm 14 and a dish shaped cover member 16secured to one end of the balance arm 14 and the formed flange 18 as bywelding or other means indicated at 17. The balance arm 14 is preferablymade of two sheet metal stampings 13 and 15 of mirror configuration,welded face to face, the flanges 18 being integral with the forward(left) ends thereof.

The support or clamp member 12 comprises two sheet metal bands or straps22 and 23 which are formed and shaped from simple strip steel, bothbeing of substantially the same length and connected together near theirmidpoints by welding or other means as indicated at 30. One end of thisassembly provides the clamping function by suitable means to enable thedevice 20 to be secured to the engine exhaust stack 11 and the other endprovides the support for pivoting the balance arm 14 and also themounting for the bumper means.

At the left hand end of the support or clamp member 12, the two bandsare apertured to receive the bolt 26 and its nut 28, the bands havingoutwardly bowed bights adjacent the ends as shown at 23 to enable theclamp member to straddle and be secured upon the stack 11 in a clampingaction.

At the right hand end of the support or clamp member 12, beyond thewelded together portions of the straps 22 and 23, the straps spread andare spaced apart to form a bifurcated structure 31 which mounts thepivot 34 and the bumper 40.

The pivot means 34 may be conventional or may comprise the pivot meansdescribed in detail in either of U.S. Pat. Nos. 2,983,216 or 4,059,045.The balance arm 14 includes a counterweight vane 21 which passes betweenthe two parts of the bifurcated structure 31 in its movement which, asseen in FIG. 2 consists of swinging between the solid line and phantomoutlines. In the solid line outlines there is no exhaust gas beingemitted from the stack 11 and the weight of the cover member 16 bringsit down upon the free end of the stack. As seen, the upper end of thestack 11 is shown spaced from the inside of the cover member 16 so thatif this situation obtains there will be no noisy clatter due to theinside of the cover member 16 striking the exhaust stack. Even duringoperation of the engine the swinging movement may permit the solid linecondition to be achieved between bursts of exhaust gas, especially inlow speed engines. In the phantom outlines, the pressure of exhaustgases and the weight of the vane 21 cause the swinging to the positionshown. In this position, the vane is arranged, according to theinvention, to come into engagement with a resilient or shock absorbingbumper rather than strike metal.

The bumper 40 is a bushing of synthetic resin such as tetrafluorethylenewhich is not readily effected by heat that is mounted on a suitablerivet 42 extending between the bifurcated straps 22 and 24 being held inplace by the cup-like washers 44 on a metal bushing 43. The bushing 40may be simply formed as a cylindrical member that extends the fulllength of the space between the straps 22 and 24 at the right hand endof the clamp member 12, if desired, but there are advantages to thestructure described in connection with FIG. 5. The constant striking ofthe bumper 40 tends to cause it to distort and flow, and the structureof FIG. 4 with the cup-like washers 44 tends to confine the bumper.

The balance arm 14 has tabs or flanges bent outwardly from the metalmembers 13 and 15 which form the balance arm, these being shown in FIG.3, for example at 17 and 19. These small tabs together form the stopmeans which has been mentioned, there being two such formations formedon the balance arm 14, one at 36 and one at 38. When the weight of thecover member 16 is dominant, as when the engine is not running, thebalance arm 14 is in the solid line position of FIG. 2 and the stopmeans 36 engages the bumper 40 at a lateral side thereof, limiting themovement of the balance arm in a counterclockwise direction around thepivot 34. This is chosen with respect to the position that the device 20is clamped to the stack 11 in such a manner that there is the clearancebetween the inside of the cover member 16 and the stack end that isillustrated in FIG. 2.

When the engine is running and the exhaust gases blow the balance armupward and force rotation thereof around the pivot in a clockwisedirection as viewed in FIG. 2, this movement is limited by the stopmeans 38 engaging the bumper 40 as shown in the broken lines of FIG. 2.The counterweight vane 21 is now substantially below the upper end ofthe stack 11.

It is seen that the bolt 26, the pivot 34 and the axis of the bumper 40are all aligned horizontally so that it is a single matter tomanufacture the support member 12 out of strips of metal that are formedin fixtures, welded and punched to receive the bolt 26, the boltsupporting the pivot 34 (not shown) and the bolt 42 which supports thebumper 40. No complex dies are needed. Further the profile of the deviceis low, carrying structure very little above the upper extent of thestack 11.

In FIGS. 6 through 9 there is illustrated another form of the inventionin which there is a replaceable bumper member instead of one which ispermanently or semi-permanently affixed as a bushing. Also the structureis somewhat simplified.

The reference character 200 designated generally the rain cover of FIGS.6 to 9 which is adapted to be clamped to an engine exhaust stack 11 inthe same manner as the device 20 previously described. In the device 20,again the support member 212 is formed out of a pair of mirrorconfiguration straps 222 and 224 of sheet metal that are easy tofabricate. The clamp member 212 has the ears or tab ends 214 formed atthe left hand end of each of the straps 222 and 224 respectively, thesebeing perforated to provide for the engagement of a bolt and nut 216 orother fastening means. The two straps 222 and 224 are welded togethernear their centers at 218 permanently to secure the straps to oneanother. Between the welded section and the ears 214 the straps areoutwardly bowed at 226 to provide a pair of bights forming a clampingsection to enable securement of the device to the stack 11 as described.

At the right hand end of the support member 212 the free ends of thestraps 222 and 224 are first bent outwardly at approximate right anglesas indicated at 232 and 234 and then parallel to one another to providethe spaced parallel bifurcated section 236 as best seen in FIGS. 8 and9. The bifurcated section 236 is perforated as shown at 238 in FIG. 8 toreceive the rivet or bolt which secures the pivot device 240 that mountsthe balance arm 242.

The balance arm 242 and pivot 240 are only shown in FIGS. 6 and 7, thepivot being conventional or of the structure of the two incorporatedpatents, its purpose being to permit free rocking of the balance arm242. The balance arm 242 is made out of a pair of identical sheet metalstampings 244 and 246 forming a front nose 248 that carries the covermember 250 and a rear counterweight vane 252. The two stampings 244 and246 are welded together face to face at several locations such as shownat 254. Integral flanges 256 bent outwardly from the stampings 244 and246 are welded to the top of the cover member 250 as indicated at 258.

The cover member 250 is of shallow dish-like inverted form and it isintended to engage over the upper end of the stack 11 without touchingthe same in the condition that the engine of which the stack 11 is theexhaust pipe is not running. This is the condition shown in FIG. 6. Theweight of the cover member 250 and the front end of the balance arm 242on the left hand side of the pivot point 240 is greater than the weightof the vane 252 so that the position of FIG. 6 is assumed by gravity.The limitation on the movement to this position and no further isbrought about by the bumper means to be described.

When the engine of the stack 11 is running, exhaust gases will blow thecover member 250 off the stack 11 and cause it to rock in a clockwisedirection about the pivot 240. This movement is also limited by thebumper means.

At the location along the clamp member or assembly 212 where the straps222 and 224 separate into the right angle bends 232 and 234 there isengaged a removable bumper member 262 which is formed of a resilientmaterial such as tetrafluorethylene. It may be molded as an integralmember or fabricated. The bumper member 262 is of channel configuration,there being a back or base portion 264 and two arm parts 266 and 268.Each of the arm parts 266 and 268 is engaged over the junction 270 ofthe two straps 222 and 224 where they are welded together and where theyare bent apart. This is best seen in the view of FIG. 9. The baseportion 264 is engaged against the right hand face of the junction 270and is located in the bifurcated section 236. Thus the arm 268 has aflat surface facing upward and the arm 266 has a flat surface facingdownward.

Since bumper member 262 is of resilient material it is easily pressedonto the junction 270 or pulled off the junction 270. To assist inholding it in place, the arms 266 and 268 have rounded projections suchas shown at 272 which help pilot the bumper member 262 onto the rear ofthe junction when it is installed and assist in its removal, theseprojections extending a slight distance below the upper edge of thesupport assembly 212 and a slight distance above the bottom edge of thesupport member or assembly 212. The projections of each arm do notextend fully across the bumper member 262 but leave a space between themwhich forms a groove at the top and bottom thereof to receive the weldedportion of the clamp member 212 as shown at 274 in FIG. 8.

The movement of the balance arm 242 is limited by the bumper member 262in cooperation with stop means that are provided on the balance arm.Tabs integral with the stampings forming the balance arm 242 are bentoutwardly from the balance arm at 280 and at 282, the former beinglocated to the right of the cover member 250 in FIG. 2 and the latterbeing located at the front edge of the vane 252. These tabs comprise thestop means mentioned.

Movement in a rocking motion around the pivot 240 in a counterclockwisedirection is limited by the stop means 280 coming into engagement withthe upper face of the arm 268. At this point of the movement which isrepresented by the solid lines of FIG. 2, the cover member 250 issuspended above the stack 11 although substantially closing the same offand does not touch the same. Movement in a rocking movement which isclockwise around the pivot 240 is limited by the stop means 282 cominginto engagement with the lower face of the arm 266. This is shown by thebroken line position of the stop means 282 in FIG. 6.

The rain cover device 200 is similar to the device 20 in that the clampmember 212 is made out of strap members with the pivot 240, thefastening means 216 and the bumper means 262 are substantially aligned.This gives the device low profile on the stack, makes it economical tomanufacture and simple to install. The vane 252 extends below the top ofthe stack 11.

Both of the structures 20 and 200 provide a rain cover assembly which iseasily installed, simple to manufacture and which substantially reducesthe clatter and noise which has been so objectionable in this type ofdevice in the past.

Variations are capable of being made without departing from the spiritor scope of the invention as defined in the appended claims.

What it is desired to secure by Letters Patent of the United Statesis:
 1. A gravity actuated protective cover device adapted to be securedupon the upstanding exhaust stack of an internal combustion engine toprevent entry of extraneous matter therein during the inoperativecondition of the engine and comprising:A. a support member adapted to besecured to the exhaust stack and having a pivot structure and resilientbumper means mounted thereon, the support member having a clampingformation to straddle and be clamped to the exhaust stack which includesadjustable fastening means, said support member being formed of a pairof metal straps of generally mirror construction connected face to face,the pivot structure, bumper means and fastening means being generallyaligned horizontally when the support member is installed on a stack,wherein the bumper means are disposed on said support member between thepivot structure and the fastening means, B. a balance arm mounted onsaid pivot structure for rocking movement about said pivot structure ina vertical plane, the balance arm having a cover member connected to thefront and thereof and a counterweight vane, the vane and cover memberbeing on opposite sides of the pivot structure, the balance arm beingadapted for said rocking movement between two positions, one of which iswith the cover member disposed engaged over the end of the exhaust stackbut without touching the same, the other position being with the covermember substantially rotated away from the stack, C. the balance armbeing heavier on the cover member side of the pivot than on the vaneside of the pivot so that the normal condition of the balance arm iswith the cover member in the first of said positions when the engine isnot operating, D. the balance arm having a pair of stop members on anedge thereof, the stop members being equally spaced from the pivot meansbut disposed at an angle relative to one another and said pivot means,E. the straps having portions thereof spaced apart to provide abifurcated portion, the pivot being located in the bifurcated portion,F. resilient bumper means disposed at said bifurcated portion andarranged in the path of movement of the stop members whereby to limitthe said rocking movement and prevent engagement of the balance arm withany other part of the cover device on the stack end.
 2. A gravityactuated protective cover device adapted to be secured upon theupstanding exhaust stack of an internal combustion engine to prevententry of extraneous matter therein during the inoperative condition ofthe engine and comprising:A. a support member adapted to be secured tothe exhaust stack and having a pivot structure and resilient bumpermeans mounted thereon, the support member having a clamping formation tostraddle and be clamped to the exhaust stack which includes adjustablefastening means, said support member being formed of a pair of metalstraps of generally mirror construction connected face to face, thepivot structure, bumper means and fastening means being generallyaligned horizontally when the support member is installed on a stack,wherein the pivot structure is disposed on said support member betweenthe fastening means and the bumper means, B. a balance arm mounted onsaid pivot structure for rocking movement about said pivot structure ina vertical plane, the balance arm having a cover member connected to thefront end thereof and a counterweight vane, the vane and cover memberbeing on opposite sides of the pivot structure, the balance arm beingadapted for said rocking movement between two positions, one of which iswith the cover member disposed engaged over the end of the exhaust stackbut without touching the same, the other position being with the covermember substantially rotated away from the stack, C. the balance armbeing heavier on the cover member side of the pivot than on the vaneside of the pivot so that the normal condition of the balance arm iswith the cover member in the first of said positions when the engine isnot operating, D. the balance arm having a pair of stop members on anedge thereof, the stop members being equally spaced from the pivot meansbut disposed at an angle relative to one another and said pivot means,E. the straps having portions thereof spaced apart to provide abifurcated portion, the pivot being located in the bifurcated portion,F. resilient bumper means disposed at said bifurcated portion andarranged in the path of movement of the stop members whereby to limitthe said rocking movement and prevent engagement of the balance arm withany other part of the cover device or the stack end.
 3. The cover deviceas claimed in claim 1 in which the bumper means comprise a channelshaped plastic member having a base and an upper and lower arm, therebeing a bend in each of the straps at one end of the bifurcated portionand the plastic member being mounted to said bends and disposed so thatthe stop members will engage the upper and lower arms respectively toeffect the limiting of said rocking movement.
 4. The cover device asclaimed in claim 3 in which at least the vane of the balance arm is madeout of stamped sheet metal members connected together face to face anddefining a plate-like structure in the plane of rocking movement of thebalance arm, the stop members comprising integral tabs bent from thesaid sheet metal members.
 5. The cover device as claimed in claim 3 inwhich the straps have a formation where they are connected face to faceat said juncture opposite said bends and the plastic member isconfigured so that the arms engage over the face to face connectedformation and the base engages the bends behind said formation.
 6. Thecover device as claimed in claim 5 in which the arms have end formationsstraddling the face to face formation and spaced apart a distance lessthan the width of said formation whereby the arms must be spaced apartto effect instatlation or removal of said plastic member relative tosaid support member.
 7. The cover device as claimed in claim 2 in whichthe bumper means comprise a plastic bushing extending between the strapsat the bifurcated section in the paths of the stop members during theirrotation whereby to engage said stop members respectively and effect thelimiting of said rocking movement.
 8. The cover device as claimed inclaim 7 in which at least the vane of the balance arm is made out ofstamped sheet metal members connected face to face and defining aplate-like structure in the plane of rocking movement of the balancearm, the stop members comprising integral tabs bent from the said sheetmetal members.
 9. The cover device as claimed in claim 8 in which thetabs are located on the edge of the vane remote from the cover member.10. The cover device as claimed in claim 4 in which the tabs are locatedon the edge of the vane nearest said cover member.